From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3E0821A5B96 for ; Wed, 16 Jul 2025 13:27:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.133 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752672436; cv=none; b=Pyt4YxMXxORvgR5GiTT2IPL2Zcf9PHFmRwZUalvQs6oP3lkdqtZOPMUleRkcqM7fZGf7FuMTPN6FDQIGvcZoP8lC9ad2+5Ib9InJfIuMRE2VArSTJNkRGJw0w1ipnnv3l9ulFDpaiD+eSOQBywDVgAa8VXKZ5ubODsFGzoBeFDA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752672436; c=relaxed/simple; bh=uhu1fRNrlk8RVXaA4erJPFp4Um5ySspJ/Be78ylhRfQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=SHJZQmv8rjUc0YcTzQxOurr8oKrmX+xZ35BV+pkMsQ3uCO1Ck6P7msSy1GT0AkjQA5lbcSaX00EB6Tvdzpk5UxytIcbqSHpkQK2RS5DcgPR9YicraRbmt4x3wFR62WjvGTNSZIcRdjzixT1vzrKgDKYVTUfsoJceLAMepBfwcO8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=lst.de; spf=none smtp.mailfrom=bombadil.srs.infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=zo2IiM72; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=lst.de Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="zo2IiM72" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From:Sender :Reply-To:Content-Type:Content-ID:Content-Description; bh=ERlSXYErquy8IupNXUxxm64+VcIv48a1OG2Qm01EuIg=; b=zo2IiM72DkzSC8uE0PP3NTvjLL PHGDpIApyQdfeqRpz5PMHsybkeiQZVHwEHKB/2nCcHMvInFRyJYNNSEoe8k03rLyYVSd6JRjDCt8f zkj6vggZwB3WKOmRHN63/udhPR0mQcNOi6MGh0hb34M4BPrraQHKk4+NARyXB/CYloLKvfi5whLrR 9q7LQmbdQNfyWgd9na8Sd6bdboAMtF7zN0ZR17Bs+sptnmFCrVjZZ1qeXMYSwgm2PKT++5YoK68Nx tsktJsw2vmDU7Grf/itkW3fNKzoNhfsxDjKWfhDG+5asIW/OisGcpkKbJoT8f59UrmjXquhdmDBw1 +fey6UFw==; Received: from 2a02-8389-2341-5b80-d601-7564-c2e0-491c.cable.dynamic.v6.surfer.at ([2a02:8389:2341:5b80:d601:7564:c2e0:491c] helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.98.2 #2 (Red Hat Linux)) id 1uc2AE-00000007n98-1CjX; Wed, 16 Jul 2025 13:27:14 +0000 From: Christoph Hellwig To: Trond Myklebust Cc: Anna Schumaker , linux-nfs@vger.kernel.org Subject: [PATCH 4/4] NFS: use a hash table for delegation lookup Date: Wed, 16 Jul 2025 15:26:34 +0200 Message-ID: <20250716132657.2167548-5-hch@lst.de> X-Mailer: git-send-email 2.47.2 In-Reply-To: <20250716132657.2167548-1-hch@lst.de> References: <20250716132657.2167548-1-hch@lst.de> Precedence: bulk X-Mailing-List: linux-nfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html nfs_delegation_find_inode currently has to walk the entire list of delegations per inode, which can become pretty large, and can become even larger when increasing the delegation watermark. Add a hash table to speed up the delegation lookup, sized as a fraction of the delegation watermark. Signed-off-by: Christoph Hellwig --- fs/nfs/client.c | 14 +++++++++++--- fs/nfs/delegation.c | 28 +++++++++++++++++++++++++++- fs/nfs/delegation.h | 3 +++ fs/nfs/nfs4client.c | 10 +++++++++- include/linux/nfs_fs_sb.h | 2 ++ 5 files changed, 52 insertions(+), 5 deletions(-) diff --git a/fs/nfs/client.c b/fs/nfs/client.c index e13eb429b8b5..5e1a5263e326 100644 --- a/fs/nfs/client.c +++ b/fs/nfs/client.c @@ -1158,6 +1158,12 @@ struct nfs_server *nfs_clone_server(struct nfs_server *source, server->fsid = fattr->fsid; + if (IS_ENABLED(CONFIG_NFS_V4) && server->delegation_hash_table) { + error = nfs4_delegation_hash_alloc(server); + if (error) + goto out_free_server; + } + nfs_sysfs_add_server(server); nfs_sysfs_link_rpc_client(server, @@ -1167,25 +1173,27 @@ struct nfs_server *nfs_clone_server(struct nfs_server *source, source->client->cl_timeout, flavor); if (error < 0) - goto out_free_server; + goto out_free_delegation_hash; /* probe the filesystem info for this server filesystem */ error = nfs_probe_server(server, fh); if (error < 0) - goto out_free_server; + goto out_free_delegation_hash; if (server->namelen == 0 || server->namelen > NFS4_MAXNAMLEN) server->namelen = NFS4_MAXNAMLEN; error = nfs_start_lockd(server); if (error < 0) - goto out_free_server; + goto out_free_delegation_hash; nfs_server_insert_lists(server); server->mount_time = jiffies; return server; +out_free_delegation_hash: + kfree(server->delegation_hash_table); out_free_server: nfs_free_server(server); return ERR_PTR(error); diff --git a/fs/nfs/delegation.c b/fs/nfs/delegation.c index ea96f77e38c2..9d3a5f29f17f 100644 --- a/fs/nfs/delegation.c +++ b/fs/nfs/delegation.c @@ -30,6 +30,13 @@ static unsigned nfs_delegation_watermark = NFS_DEFAULT_DELEGATION_WATERMARK; module_param_named(delegation_watermark, nfs_delegation_watermark, uint, 0644); +static struct hlist_head *nfs_delegation_hash(struct nfs_server *server, + const struct nfs_fh *fhandle) +{ + return server->delegation_hash_table + + (nfs_fhandle_hash(fhandle) & server->delegation_hash_mask); +} + static void __nfs_free_delegation(struct nfs_delegation *delegation) { put_cred(delegation->cred); @@ -367,6 +374,7 @@ nfs_detach_delegation_locked(struct nfs_inode *nfsi, spin_unlock(&delegation->lock); return NULL; } + hlist_del_init_rcu(&delegation->hash); list_del_rcu(&delegation->super_list); delegation->inode = NULL; rcu_assign_pointer(nfsi->delegation, NULL); @@ -529,6 +537,8 @@ int nfs_inode_set_delegation(struct inode *inode, const struct cred *cred, spin_unlock(&inode->i_lock); list_add_tail_rcu(&delegation->super_list, &server->delegations); + hlist_add_head_rcu(&delegation->hash, + nfs_delegation_hash(server, &NFS_I(inode)->fh)); rcu_assign_pointer(nfsi->delegation, delegation); delegation = NULL; @@ -1166,11 +1176,12 @@ static struct inode * nfs_delegation_find_inode_server(struct nfs_server *server, const struct nfs_fh *fhandle) { + struct hlist_head *head = nfs_delegation_hash(server, fhandle); struct nfs_delegation *delegation; struct super_block *freeme = NULL; struct inode *res = NULL; - list_for_each_entry_rcu(delegation, &server->delegations, super_list) { + hlist_for_each_entry_rcu(delegation, head, hash) { spin_lock(&delegation->lock); if (delegation->inode != NULL && !test_bit(NFS_DELEGATION_REVOKED, &delegation->flags) && @@ -1577,3 +1588,18 @@ bool nfs4_delegation_flush_on_close(const struct inode *inode) rcu_read_unlock(); return ret; } + +int nfs4_delegation_hash_alloc(struct nfs_server *server) +{ + int delegation_buckets, i; + + delegation_buckets = roundup_pow_of_two(nfs_delegation_watermark / 16); + server->delegation_hash_mask = delegation_buckets - 1; + server->delegation_hash_table = kmalloc_array(delegation_buckets, + sizeof(*server->delegation_hash_table), GFP_KERNEL); + if (!server->delegation_hash_table) + return -ENOMEM; + for (i = 0; i < delegation_buckets; i++) + INIT_HLIST_HEAD(&server->delegation_hash_table[i]); + return 0; +} diff --git a/fs/nfs/delegation.h b/fs/nfs/delegation.h index 8ff5ab9c5c25..08ec2e9c68a4 100644 --- a/fs/nfs/delegation.h +++ b/fs/nfs/delegation.h @@ -14,6 +14,7 @@ * NFSv4 delegation */ struct nfs_delegation { + struct hlist_node hash; struct list_head super_list; const struct cred *cred; struct inode *inode; @@ -123,4 +124,6 @@ static inline int nfs_have_delegated_mtime(struct inode *inode) NFS_DELEGATION_FLAG_TIME); } +int nfs4_delegation_hash_alloc(struct nfs_server *server); + #endif diff --git a/fs/nfs/nfs4client.c b/fs/nfs/nfs4client.c index 2e623da1a787..31dc0d40209a 100644 --- a/fs/nfs/nfs4client.c +++ b/fs/nfs/nfs4client.c @@ -802,6 +802,7 @@ static void nfs4_destroy_server(struct nfs_server *server) unset_pnfs_layoutdriver(server); nfs4_purge_state_owners(server, &freeme); nfs4_free_state_owners(&freeme); + kfree(server->delegation_hash_table); } /* @@ -1096,9 +1097,14 @@ static int nfs4_server_common_setup(struct nfs_server *server, { int error; + error = nfs4_delegation_hash_alloc(server); + if (error) + return error; + /* data servers support only a subset of NFSv4.1 */ + error = -EPROTONOSUPPORT; if (is_ds_only_client(server->nfs_client)) - return -EPROTONOSUPPORT; + goto out; /* We must ensure the session is initialised first */ error = nfs4_init_session(server->nfs_client); @@ -1130,7 +1136,9 @@ static int nfs4_server_common_setup(struct nfs_server *server, nfs_server_insert_lists(server); server->mount_time = jiffies; server->destroy = nfs4_destroy_server; + return 0; out: + kfree(server->delegation_hash_table); return error; } diff --git a/include/linux/nfs_fs_sb.h b/include/linux/nfs_fs_sb.h index a9b44f12623f..d30c0245031c 100644 --- a/include/linux/nfs_fs_sb.h +++ b/include/linux/nfs_fs_sb.h @@ -255,6 +255,8 @@ struct nfs_server { struct list_head layouts; struct list_head delegations; atomic_long_t nr_active_delegations; + unsigned int delegation_hash_mask; + struct hlist_head *delegation_hash_table; struct list_head ss_copies; struct list_head ss_src_copies; -- 2.47.2